Alzheimer's disease: How close are we to solving the problem?
It is very rare that there are days when there is not a single report about a study on Alzheimer's disease in medical news feeds. All over the world, scientists are actively searching for methods to prevent and treat this serious disease, which affects almost 36 million people worldwide. This article assesses the progress of this research area.
First described in 1906 by Dr. Alois Alzheimer (Alois Alzheimer), Alzheimer's disease is the most common form of dementia, diagnosed in 60-80% of cases. It is characterized by memory and thinking disorders, as well as behavioral problems. Most often, the disease first manifests itself at the age of 65 and older, although there are also cases of so-called early Alzheimer's disease, manifesting at the age of 40-50 years.
Alzheimer's disease is a progressive disease: in the initial stages, it manifests itself with moderate memory impairments, which worsen over time and eventually lead to the inability of patients to engage in dialogue and respond to their environment.
There are treatments for Alzheimer's disease that have been approved by the U.S. Food and Drug Administration (FDA). For example, cholinesterase inhibitors and memantine facilitate the manifestations of memory and thinking disorders. However, these drugs have only a symptomatic effect and do not cure the disease.
Today in the United States, about 5 million people (most women) aged 65 and older are living with a diagnosis of Alzheimer's disease. This figure is expected to increase to 16 million by 2050. The world statistics look about the same, and by 2050 the number of patients with this disease in the world will reach 115 million.
In the United States, Alzheimer's disease, which annually claims more than half a million lives, is in sixth place in the list of leading causes of death. More people die from it than from prostate cancer and breast cancer combined. Obviously, the reason for this is not the lack of perseverance of scientists dealing with the problem: only in the last month Medical News Today published the results of three promising studies – on the restoration of memory disorders and learning ability in mice with Alzheimer's disease model, how vitamin D deficiency can increase the risk of dementia, and how DNA methylation in neurons It is associated with Alzheimer's disease. However, what conclusions and practical results have all these studies led to?
Preventing the formation of plaques and strands and targeting themAs with any other disease, the key to identifying methods of prevention and treatment of Alzheimer's disease is to find out the exact causes of its development.
The results of earlier studies have shown that Alzheimer's disease occurs when abnormal structures of two types – plaques and cords – damage and kill nerve cells, which leads to memory and thinking disorders associated with the disease, as well as behavioral problems.
Plaques are aggregates of beta-amyloid protein molecules that accumulate between nerve cells. Strands are formed from tangled tau protein fibers deposited inside brain cells.
Despite the fact that experts have not yet come to a consensus on the role of plaques and strands in the development of Alzheimer's disease, research results indicate that their accumulation begins long before the first symptoms of the disease appear. Based on this, some experts are inclined to believe that in the fight against Alzheimer's disease, the most effective approach is early intervention aimed at preventing the formation of abnormal structures in brain tissue.
At the same time, the results of some studies indicate the effectiveness of Alzheimer's disease treatment by affecting these structures – for example, there is evidence that an increase in the number of synapses between brain cells suppresses the accumulation of amyloid plaques.
There is also evidence in favor of the fact that lifestyle features, such as chronic lack of sleep and the consumption of grilled meat, may be risk factors for the development of Alzheimer's disease. Whereas regular coffee consumption, on the contrary, can slow down the process of forming strands.
Alzheimer's disease and genesMore recently, scientists have received evidence that genes play an important role in the development of Alzheimer's disease.
Studies have shown that most cases of early manifestation of the disease have a hereditary (family) character. It turned out that the cause of the development of the familial form of Alzheimer's disease may be certain mutations on the 21st, 14th or 1st chromosomes, causing the formation of abnormal structures in brain tissue.
As for the late form of Alzheimer's disease, the relationship between its development and the apolipoprotein E gene was revealed. One of the forms of this gene, APOE4, is associated with an increased risk of developing the disease. According to the latest data, this relationship is most pronounced in women.
In a study published last year in Nature Genetics, 11 genes were identified that potentially increase the risk of developing Alzheimer's disease. At the same time, a parallel study found that one of the variants of the ABCA7 gene is a risk factor for the development of the disease in African Americans.
The mechanisms by which the identified genes increase the risk of developing Alzheimer's disease are currently unclear. However, the discovery of each new genetic variant gives scientists new data, thereby increasing the likelihood of effective methods of prevention and treatment of the disease.
Recently, the problem of Alzheimer's disease has received more attention than ever, which has provided significant progress in this area. Only in the last 20 years has the role of beta-amyloid and tau protein in the development of Alzheimer's disease been revealed, the FDA has approved the first drug that facilitates the manifestations of memory and thinking disorders, and the first mouse model and the first potential blood test method for the diagnosis of the disease have been developed. Also, to date, a fairly large number of drugs for the treatment of Alzheimer's disease are at different stages of development and effectiveness testing.
Overcoming difficultiesHowever, experts note that, despite significant progress, there are still many difficulties ahead.
Perhaps an increase in funding would help overcome them: in the United States, the National Institutes of Health last year allocated $504 million for the study of Alzheimer's disease, while 10 times more, more than $5 billion, for research in the field of oncology (including $674 million for breast cancer alone).
In addition to the need to attract additional funding, there are certain difficulties in attracting volunteers for the 300 clinical trials currently underway.
One of the attempts to solve this problem is the free service created by the Association for the Study of Alzheimer's Disease for the individualized selection of clinical trials TrialMatch, which can be used by patients, their family members and healthy volunteers. Participation in such studies allows everyone to play an active role in the development of healthcare and increase the chances that sooner or later (but, according to experts, undoubtedly) effective methods of treating Alzheimer's disease and other types of dementia will be developed.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to Medical News Today:
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22.08.2014